<!DOCTYPE html>
<html lang="en">
    <head>
        <title></title>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        
    </head>
    <body>
        <form action="" method="post">
            <input type="text" name="uname" id="" value="请输入用户名" required >
            <input type="text" name="password" pattern="\d+" required>
            <select name="location" id="selLocation"  > <!--  -->
                <option value="Sunnyvale, CA">Sunnyvale</option> 
                <option value="Los Angeles, CA">Los Angeles</option>
                <option value="Mountain View, CA">Mountain View</option>
                <option value="">China</option>
                <option>Australia</option>
            </select>
            <button id="myChangeBtn" >改变</button>
            <input type="submit" value="提交">
        </form>
        <input type="text" id="myInput" value="你好吗，请问这个事件" size="30">
        
    </body>
    <script src="js/chp14-1form.js"></script>
</html>